1. Field of the Invention
The present invention relates generally to an anti-theft tag structure, and more particularly, to an RFID anti-theft tag structure.
2. The Prior Arts
In accordance with the development of the semiconductor industry, radio frequency identification chips (RFIC) which are small and have strong capabilities have been widely employed in radio frequency identification (RFID) field, such as entry control, ID card, supply chain management, electronic toll collection (ETC), and real-time locating system (RTLS).
Furthermore, in order to set up an effective anti-theft mechanism for avoiding commodities from being illegally taken away, RFID tags are usually attached to commodities in facilitation with the detection devices equipped at the exits of stores. When any commodity carrying such an RFID tag is illegally brought passing by the detection devices, the RFID tag will emit a signal, and the signal can be detected by the detection devices, and correspondingly an alarm lamp/bell will be enabled. In such a way, the commodity can be protected from being illegally taken away.
Referring to FIG. 1, there is shown a conventional anti-theft tag structure. As shown in FIG. 1, the conventional anti-theft tag structure includes a first protective layer 10, a paper sheltering layer 20, a permanent-magnetic alloy film 30, a sticky film 40, at least one alloy sheet 50, and a second protective layer 60 sequentially disposed one on another from bottom to upper side. The alloy sheet 50 can be repetitively magnetized and demagnetized. The sticky film 40 is employed for separating the permanent-magnetic alloy film 30 from the alloy sheet 50, and supporting the alloy sheet 50. The paper sheltering layer 20 is adapted for providing a sheltering function. The first protective layer 10 and the second protective layer 60 are provided for covering the paper sheltering layer 20, the permanent-magnetic alloy film 30, the sticky film 40, and the alloy sheet 50, and providing a protection thereto.
The permanent-magnetic alloy film 30 is adapted for emitting a signal, and an external detection device (not shown in the drawing) is provided for detecting the signal emitted from the permanent-magnetic alloy film 30. However, when the alloy sheet 50 is magnetized, the alloy sheet 50 is magnetic and is thus adapted to disturb the signal emitted from the permanent-magnetic alloy film 30, so that the signal cannot be detected by the detection device. When the alloy sheet 50 is demagnetized, the alloy sheet 50 is nonmagnetic, and therefore the signal emitted from the permanent-magnetic alloy film 30 can be detected by the detection device so that the alarm is enabled to cause an alert.
Accordingly, an anti-theft tag containing such a nonmagnetic alloy sheet can be attached to a commodity. In case such a commodity is illegally taken away via the detection device, the alarm will be enabled to generate an alert. When the commodity is purchased by a customer, the cashier can magnetize the alloy sheet contained in the anti-theft tag, so that the commodity can be taken away via the detection device without enabling the alarm.
However, although the conventional anti-theft tag structure includes an RFID function and an anti-theft tag function, these two functions are independently realized. Such a conventional anti-theft tag structure requires not only a higher cost, but also a relatively complicated assembly process, which may decrease the reliability and yield of the products. As such, an anti-theft tag structure integrally combining the RFID function and the anti-theft tag function for solving the problem of the conventional anti-theft tag is highly desired.